below is the error i get in thesitmap of one of my sites.

Hello, below is the error i get in thesitmap of one of my sites. It has been working well, I do not know how this came about. Kindly help me out.

<b>Warning</b>: readfile() has been disabled for security reasons in <b>/home/freelan/public_html/wp-content/plugins/wpmu-dev-seo/wds-files/wds-sitemaps/wds-sitemaps.php</b> on line <b>501</b>

Thanks,

Louis